The Dangers of Rock Dust

By Glen Kuban

Keywords: Silicosis, pulmonary fibroisis, lung disease

Many collectors use a mechanical rock saw to cut, trim, or
abrade rocks and fossils in the field or lab. Dangers of
this activity include flying rock chips, wounds from the
blade itself or broken blades, and ruck dust, which is
extremely dangerous to inhale. Always read and understand
the proper operation of any mechanical tool before using it.
Whenever cutting or grinding rock, wear protective eye goggles.
Also wear a good respirator, or use a dust collection system, to
avoid inhaling rock dust, which accumulates in the lungs and
can cause a variety of serious illnesses.

For those not convinced that rock dust is a serious danger,
or that they can get away with not wearing a respirator or
working under a hood (if working indorrs), I encourage
you to read the messages below. The original message was
posted on 7-14-97 in the Rocks and Fossils Newsgroups, and
my reply was sent to that list as well as the Dinosaur List,
VrtPaleo, and Fossil Nuts.

The original message I am responding to was posted in Rocks and
Fossils, but I am sending my response to other paleo-related
lists as well, because I feel this is an important safety issue.
It affects anyone who even occassionally cuts rocks or fossils,
or does fossil preparation work. It will be very worthwhile if
it prevents even one person from suffering lung problems or dying
prematurely. With that deliberately omenous introduction, let
me quote the post that prompted my response:
Pete Richards wrote:
> Last night I spent an hour cutting sandstone sidewalk
>blocks with a composition blade made of fibreglass and
>carborundum grit. This is a dry saw and it was a still
>night and clouds of dust were all around. Some of it hung
>in the air for minutes. I am not really concerned about a
>one-shot exposure, but it did make me wonder if this is the
>size of silica which DOES represent a health hazard. Of course,
>I do not know for sure that the fine dust was silica, as opposed
>to calcium carbonate (the cement in the sandstone) or material
>from the saw blade...
It's funny, or really not so funny, that you should write now.
I'm suffering a chronic lung irritation, and seeing doctors now,
because of the results of a similar incident. In short, yes, one
or a few exposures to significant amounts of freshly-cut rock
dust can cause serious problems. Silicosis is only one of many
lung problems that can be caused by rock dust, many of which
(like fibrosis) can occur no matter what the composition of the
rock. Wearing a good respirator or hood with dust collector if
working indoors is a must. If you don't have the proper safety
equipment, don't cut the rock!
Unfortunately, I found out the hard way, I hope everyone learns
from my mistakes. About a year ago our fossil club went to
Ontario to collect trilobites, and we took along a diamond rock
saw. I only sawed out a few trilobites for fellow members
(without wearing a mask; I forgot to bring one) and I tried to
not inhale the dust. However, large clouds of it were kicked up
each time, and it was impossible to avoid inhaling quite a bit of
it. My the next morning I had significant lung irritation, and
have had it ever since--some days worse than others. I have
frequent coughing and uncomfortable sensation in my upper chest.
After this went on a few weeks, I went to a doctor, not knowing
if I had contracted a bacteria, fungus, or other microbe at the
quarry, or just had accumulated too much dust in my lungs. An
x-ray was clear, but that is not unusual in such cases (it
sometimes takes years for fibosis, TB, cancer, and other diseases
to develop). Apparently the rock dust itself is the cause the
current lung irriration, and it may never get better. In fact,
it may worsen into other conditions, as explained below.
Many people assume years of exposure to rock dust is needed to
cause serious problems, and this is generally true when dealing
with wind-blown, low concentration dust, which usually has
already been weathered to some degree. But not so with freshly
cut rock. After I started having my problems, I began talking
to doctors and doing lots of reading. I also talked to an uncle
who used to work in a quarry, and is now dying of pulmonary
fibrosis at the age of 55. I'm now going to his doctor.
It turns out that not only do rock particles of any composition
tend to stay and accumulate in the lungs, but _freshly cut_ rock
is the worst, and extremely pernicious. Even one or a few incidents
of significant inhalation of such dust can cause lung irritation
and a start process of increasingly serious lung damage. The
microscopic particles are like millions of razor-edged shards that
damage lung tissue directly, as well as create conditions promoting
the development of TB, microplasms, fibrosis, and cancer.
Experiments with rats and other animals have shown that
inhallation of fresh cut rock dust is far more damaging than worn
rock dust of any composition, and leads to far greater rates of
several diseases, including pulmonary fibrosis and lung cancer.
(But even accumulations of worn rock dust in the lungs greatly
increased chances of lung diseases).
I've also made many fossil molds and casts over the years, and
although I often wore a mask while working with plaster, but
sometimes did not. I may well have accumulated plaster in my
lungs as well, which may have contributed to or aggravated my
lung condition. Plaster hardens when in contact with moisture,
wherever it occurs, including one's lungs. But I did not have
the constant lung irritation until after the Ontario trip using
the rock saw (on hard shales and siltstones), and have had it
ever since.
I have another apppointment with a pulmonary doctor on Thursday,
but from what I have learned such damage is generally irreversible,
the best I may hope for is to have my condition not get worse.
I may have to live with lung irritation and chronic caugh for the
rest of my life, plus increased chances for the serious conditions
I listed above.
So PLEASE, whenever you are cutting or grinding rock of any kind,
ALWAYS wear a respirator (not just a cheap dust mask). If
working indoors, use a dust collecting hood, or don't do it.
Your health is not worth any rock or fossil.
There are serious inhallation dangers in the lab also, including
solvents, urethanes, glues, and other chemicals used on prep work.
These too can have accumulative effects, and lead to a variety
of heath problems. Work with such chemicals only with very good
ventillation, or under a hood, or don't do it. Again, a rock or
fossil is not worth your health.
If I scared anyone, I can't feel too bad, because I wish someone
had scared me before I did what I did, and may have to pay the
price the rest of my life.
Pete, in your case, I hope you do not have any problems, and can
only urge you not to do it again, at least not without wearing a
respirator. The dust you created by cutting sandstone probably
included a mixture of siliceous sand particles, calcium
carbonate particles, (from the cement between the sand grains),
and fibers from the fibrous saw blade. All could be dangerous to
inhale.
Thank you.
Glen Kuban